SO vs XLK: Correlation
Southern Company (SO) and Technology Select Sector SPDR Fund (XLK) show a negative relationship: their 3-year correlation of weekly returns is -0.20.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are SO and XLK?
Across a 3-year window, the weekly returns of SO and XLK correlate at -0.20, negative, meaning they tend to move in opposite directions. Recent behaviour matches the longer record: -0.29 over 1 year against -0.20 over 3. Stretching to 5 years gives 0.05, with an annualized covariance of -77.6 %².
Within SO's tracked universe of 48 assets, XLK comes in at #33 by 3-year correlation. The last year tells two different stories: XLK led by 44.8 percentage points, -1.4% for SO against +43.4% for XLK. The relationship is regime-dependent: the rolling one-year correlation swung between -0.35 and 0.27 over the past three years, so this pair behaves very differently depending on the market environment.
How is this computed?
Pearson correlation on weekly returns: ρ(A,B) = cov(rA, rB) / (σA · σB), over windows of 52, 156 and 260 weeks. Covariance is annualized (×52) and expressed in %². Full definitions on the methodology page.
SO vs XLK: side by side
| SO (Southern Company) | XLK (Technology Select Sector SPDR Fund) | |
|---|---|---|
| 1-year return | -1.4% | +43.4% |
| 5-year return | +62.6% | +145.2% |
| Volatility (ann.) | 16.5% | 24.0% |
| Beta vs S&P 500 | -0.02 | 1.50 |
| Max drawdown (3Y) | -15.0% | -25.7% |
| Market cap | $102.4B | – |
| P/E (trailing) | 21.7 | – |
| Dividend yield | 3.32% | 0.45% |
| Expense ratio | – | 0.08% |
| Assets under management | – | $115.4B |
| Sector / category | Utilities | Sector ETF |
On the fund side, XLK sits in the Technology category at State Street Investment Management, with $115.4B under management, 73 holdings, a 0.08% expense ratio, a 0.45% trailing dividend yield.
Year-by-year returns
| Year | SO | XLK |
|---|---|---|
| 2022 | +8.2% | -27.7% |
| 2023 | +2.2% | +56.0% |
| 2024 | +21.7% | +21.6% |
| 2025 | +9.5% | +24.6% |
| 2026 | +4.6% | +31.3% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are SO and XLK good diversifiers for each other?
By historical standards, yes. A correlation of -0.20 means the two rarely move for the same reasons.
FAQ
What is the correlation between SO and XLK?
The SO/XLK correlation stands at -0.20 on a 3-year window (1 year: -0.29, 5 years: 0.05), computed from weekly returns as of 2026-08-27.
Is XLK a good diversifier for SO?
By historical standards, yes. A correlation of -0.20 means the two rarely move for the same reasons.
What does a correlation of -0.20 mean?
A reading of -0.20 sits on a scale from −1 (opposite moves) through 0 (unrelated) to +1 (identical moves). Correlation captures direction, not magnitude or performance.
Use this data
$ curl https://www.pairbook.io/api/v1/pairs/so-vs-xlk.json
Markdown for the live badge, attribution link included:
[](https://www.pairbook.io/pair/so-vs-xlk/)
The core API is free. Terms and every endpoint in the API documentation.
Related comparisons
Hubs: SO correlations · XLK correlations
